The historiography of modern Irish Catholicism owes a considerable debt to the author of this book, Thomas J. Morrissey, a Jesuit and educationist, who has been one of its most prolific contributors. His extraordinary output includes many biographies of leading figures in church and society; nor is this book even his latest offering, as a biography of archbishop Daniel Murray of Dublin was published in 2018. Morrissey's oeuvre is testimony to the fact that the traditional church history genre of biographies of great churchmen – for all its limitations – still has many things to offer.

Edward Cahill (1868–1941), like Morrissey a Jesuit, educationist, and Limerickman, is known in history mainly for having founded the An Ríoghacht movement in 1926, and as a contributor to the drafting of Éamon de Valera's 1937 constitution. The first part of Cahill's career was spent mostly at Mungret College in Limerick, especially at the Apostolic School, a minor seminary for boys destined for foreign dioceses. In 1925 he was moved to Milltown Park in Dublin, where he became professor of church history and sociology and a spiritual director. It was there that he wrote his two main works, Freemasonry and the anti-Christian movement (1929) and The framework of a Christian state (1932). Cahill was out of step with many of his confrères and was often at cross-purposes with his superiors. A sophisticated, pro-Treaty elite among the Dublin Jesuits regarded him as a naive hick and an embarrassment to the society; Morrissey's biography is an attempt to redress the balance.

Cahill's republican sympathies coalesced with a strong belief in Catholicism as a dynamic force for the recreation of society. He thought this was urgently needed in the Irish Free State, that ‘anomaly of a profoundly Catholic people deprived of many of the external features of a Catholic civilisation’ (p. 122). The author gives an engaging and sympathetic account of this imaginative thinker, whose views and activities are best understood through the prism of Catholic Action: the drive to mobilise lay Catholics for the Catholicisation of society. This aim could be realised through such things as the promotion of family-oriented legislation, censorship of publications (ironically Cahill was himself regularly on the receiving end of ecclesiastical censorship), and corporatism/vocationalism. In its Irish republican variant, it also involved redistribution of the land to small farmers, and de-anglicisation of society and the economy, the latter exemplified by the An Ríoghacht-sponsored third minority report to the 1934–1938 banking inquiry. Among Cahill's more imaginative schemes was a new Irish-speaking religious order that would, like the pioneering medieval Cistercians, run agricultural colonies for young men.

A risk of the biographical genre is that the protagonist is depicted primarily as an individual and not as representative of wider phenomena, and the current book has not fully avoided this shortcoming. A more sustained discussion of the context of Catholic Action as an international movement and of the ambivalent responses it elicited in Ireland would have strengthened the analysis. Cahill is portrayed as a model Jesuit, but this category should itself be historicised: what was the model image of a good Jesuit in Cahill's time, and how did this affect him? Also, Cahill is described as a pioneer of social Catholicism, but internationally the social priest was a common feature of the clerical generation to which he belonged. An exploration of this context might have enhanced our understanding of him and, possibly, identified him as a figure of interest for the international historiography of social Catholicism.

There are a few other issues. Cahill was an anti-Semite whose writings on the topic were censored by his order. Morrissey's treatment of this is sober, perhaps too sober, as it does not assess how important this aspect was to Cahill's vision of a Christian Ireland. Cahill was also a major disseminator of masonic conspiracy theories. It is much to Morrissey's credit that he has reintroduced to historiography a figure who helped shape a significant strand of religious and political activism in the first decades of independence.